JPS63157778A - Method and device for cutting solid material by laser projection - Google Patents

Abstract

PURPOSE:To cut easily and safely without the need for a large sized device by moving the focusing position of a laser beam according to the cutting depth each time and cutting with removing a dross after cutting each time as well. CONSTITUTION:A work head 2 is adjusted so that the focusing position of a laser beam 5 comes to the surface of a concrete material 6 and when a laser cutting device 1 is moved along the cutting position of the concrete material 6, the groove 11 cut in a depth (h1) is formed. The dross caused at this time is blown off by the assisting gas injected from an assisting gas nozzle 9, cooled inside the groove 11, attained to a glass like dross and fixed to the wall of the groove 11. The fixed dross 10 is discharged to the external part by being sucked in a cleaning device 13 by being crushed by being cut with a rotary cutter 12. The device 1 returns to a cutting start point and a signal is transmitted to a control device 14 with a sensor detecting the depth h1 of the groove 11. The work head 2 is controlled by the device 14 and the groove in the depth h1+h2 is formed on the concrete material 6.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention makes it possible to obtain the same result as cutting with a high-power laser by repeatedly cutting the same cutting position with a low-power laser. The present invention relates to a method for cutting solid materials by laser irradiation and an apparatus therefor.

[Conventional technology]

Among solid materials, there are still few actual examples of cutting and disassembling reinforced concrete, steel-framed reinforced concrete, fiber-reinforced concrete, fiber concrete, concrete, mortar, and structures using these materials using laser beams, and at present, there are few practical examples of cutting and disassembling solid materials using laser beams. It's on the staircase.

In addition, the currently used cutting methods require factors that improve cutting performance: laser output, cutting speed, focal length of the condensing lens or condensing mirror, focusing position, laser beam mode (intensity distribution), The pressure of the assist gas, its type, etc. are used as parameters, and cutting is performed by changing and combining these parameters. However, in these cutting methods, the object is cut by moving a laser cutting device in one direction with its focal position fixed in the cutting depth direction. As a device for cutting in this way, there is a device disclosed in Japanese Patent Application Laid-Open No. 59-194805 shown in Fig. 5.
Is there something that was disclosed in the publication?

To briefly explain this, in the figure, a laser beam 1 is emitted from a laser oscillator (not shown), passes through a torch section 2, and irradiates a concrete material 3, which is an object to be cut. P is an irradiation point that is almost the focus of the laser beam l, and the concrete material 3 melts inward from this point. A replenishment material such as MgO is supplied to this melt from a replenishment supply device 5 through a nozzle 4, mixed with the molten concrete, and becomes brittle slag 6 after cooling. This molten slag accumulates in the groove 7 created by the fusing, and is removed by rotating the wire brush 8. A crushing agent 9 for breaking the concrete material 3 is charged into the groove 7 from which the slag has been removed.

The above-mentioned parts are arranged in a row on the machine frame 10 to constitute a laser cutting device, and this device is moved in the direction of arrow A to cut concrete material. ′ [Problems to be solved by the present invention] However, in such a conventional cutting method,
This method cuts concrete by moving the laser cutting device in one direction without changing the laser focus position in the direction of the cutting depth, so this device and method can greatly improve cutting processability. In this case, the only option is to either slow down the moving speed of the device or increase the laser output. Slowing down the moving speed of the device will take time to cut, increasing the laser output will require larger laser oscillators, power supplies, etc., and transportation of the entire device to the site will be necessary if work is to be done outside of a designated location such as a factory. This becomes difficult and the equipment becomes expensive.

Furthermore, if the laser output is increased, a stable output cannot be obtained, and currently commercially available CO2 lasers have an output of up to 10 KW, and other lasers have an output of 3 KW or less.

This invention has been made in view of the above-mentioned conventional problems, and the above-mentioned problems can be solved by repeatedly melting the same cutting position while changing the focal position of the laser in the direction of the cutting depth. It aims to solve the problem.

[Means for Solving the Problems] When cutting a solid material by irradiating a laser, the present invention adjusts the focus position of the laser beam according to the depth of each cut in order to repeatedly cut the same cutting position. A method for cutting solid materials in which the solid material is cut while moving in the direction of the melting depth and removing slag produced by melting of the solid material after each melting using a rotary cutter, shot blasting, etc., and an apparatus used to carry out this method. The present invention is equipped with a laser irradiation device that can move the focal position of the laser beam in the direction of the melting depth of the solid material, and a rotary cutter or shot blasting device for removing and cleaning slag from the melted solid material. This is a laser cutting device.

[Effect]

First, when the focus position of the laser beam 1 is set on the surface of the solid material to be cut and the laser cutting device is moved along the cutting position while irradiating the surface, the solid material will be cut in inverse proportion to the moving speed of the cutting device. If the solid material is concrete, for example, the molten slag that has been cooled and solidified after being fused is fixed in the groove. Therefore, this molten slag is removed using a rotary cutter, shot blasting, etc., and the grooves are cleaned. Next, the laser cutting device is moved again along the same cutting position as the previous time while moving the focal point of the laser beam to the bottom of the cleaned groove and irradiating it, so that the groove is cut deeper and deeper from the bottom. Deep grooves are formed. Then, the slag generated again is removed by the above-mentioned means. Next, by setting the focal point of the laser at the bottom of this deeper groove and repeating the same cutting, the depth of the cut groove reaches the back surface of the solid material, and the solid material is cut.

By repeating cutting with a low-power laser in this way, the same result as cutting with a high-power laser can be obtained. The device used at this time is a low-power laser cutting device that has means that allows the focal position of the laser beam to be moved.

〔Example〕

The present invention will be explained below based on the drawings. 1 to 4 are diagrams showing embodiments of the present invention.

First, to explain the configuration, in FIG. 1, 1 is a laser cutting device, and 2 is a processing head as the laser irradiation device. This processing head 2 includes a reflecting mirror 3. A condensing mirror 4 and the like are installed inside, so that a laser beam 5 emitted from a laser oscillator (not shown) is reflected and condensed to irradiate it onto a concrete material 6, which is a solid material.

Reference numeral 7 designates a protective tube for the processing head 2, which is provided to prevent dust and smoke generated when the concrete 6 is melted from blocking the laser beam and reducing the performance of the laser. This prevents these fumes from entering the path of the laser beam 5. 9 is an assist gas nozzle, which is installed to spray assist gas such as 02 toward the laser beam focal point to hasten the melting of reinforcing bars in concrete and blow away molten dross. It is. In addition, when this dross is cooled, it becomes a glass-like solid slag.
As a result, it fills the groove II formed by fusing and is fixed to the wall surface of the groove II. Therefore, this molten slag 10 is cut and crushed by a rotary cutter 12 provided in the laser cutting device 1, and is absorbed by a cleaning device 13 and discharged to the outside.

Reference numeral 14 denotes a computer control device that moves the processing head 2 in the fusing depth direction based on the depth h of the groove 11 detected by a sensor (not shown), and automatically controls the focal position of the laser beam. 15 is an operating ring connected to a remote control device (not shown).

In this embodiment, the focal length of the laser beam 5 focused by the focusing mirror 4 is set to about 1 m in order to obtain a large fusing depth.

Next, the operation will be explained.

First, the focus position of the laser beam 5 is on the concrete material 6.
When the processing head 2 is adjusted so that it comes to the surface of the concrete material 6, and then the laser cutting device 1 is moved at a predetermined speed along the cutting position of the concrete material, the concrete material 6 has a depth related to the moving speed, which will be described later. A groove 11 is formed. The dross generated at this time is blown away from the vicinity of the focal point by the assist gas blown from the assist gas nozzle 9, cools within the groove 11, becomes glass-like slag, and adheres to the wall of the groove 11. The fixed molten slag lO is cut and crushed by a rotary cutter 12 that moves together with the device 1, and is sucked into a cleaning device 13 and discharged to the outside. In this way, when the cutting position of the concrete material 6 is fused so that the groove 11 of depth is formed, the device 1
returns to the cutting starting point of the cutting position, and at the same time a sensor (not shown) detects the depth of the groove 11 and sends the detection signal to the computer control device 14, which controls the processing gutter 2. , the focal position of the laser beam 5 is moved in the depth direction so that it comes to the bottom of the groove 11. Next, the laser cutting device l moves again at the same cutting position of the concrete material 6 as the previous time at a predetermined speed, and as it moves, the concrete material 6 is further melted and deepened to form a groove of +h2, and the groove is The molten slag inside is further cut and crushed by a rotary cutter 12 that protrudes from the device 1 by a distance h2, and is discharged by a cleaning device 13.

As the laser cutting device 1 repeats such a fusing operation, the depth of the groove 11 increases, and the concrete material 6
is cut at the cutting position.

A second embodiment is shown in FIG. 2 (the same parts as in the previous embodiment are given the same reference numerals and redundant explanations will be omitted).

In this embodiment, a plasto nozzle 17 is provided in place of the rotary cutter 12 in the previous embodiment, from which sand or grid is injected to blow away the dross 10, and the powder mixture of the sand or grid and dross is transferred to a suction tube. 18 into the cleaning device 13, and the collected powder is conveyed by compressed air through the supply pipe 19 to the plus 1 nozzle 17 again.
It is designed to be ejected from. 2° is a sealing plate which partitions the groove 11 to define a sealed space 21 when sucking the powder.

Further, the operation of the processing head 2 and the method of repeatedly fusing the same cutting position are the same as in the first embodiment.

FIG. 3 shows a third embodiment. This is the same as the second embodiment except that the suction pipe 18 for collecting sand and grid is omitted, and the supply pipe 18 is connected to the blasting material tank 22.
9 from the blast nozzle 17, and the blasting material such as sand is not reused. Therefore, although the structure is simpler than that of the second embodiment, this device is used when the blown dust does not cause problems in the working environment.

FIG. 4 shows the relationship between the laser output and the depth of the fused groove 11 (hl++12+...) when the same cutting position is repeatedly fused in the above embodiment. 2 with a laser with an output of 5KW.
This shows that the cutting depth (1-time cutting value of 45 mm) and 2-time cutting value (85 mm) when melt-cutting is performed twice is larger than the cutting depth (82 mm) when melt-cutting is performed once with a laser with an output of 10 KW. (However, in both cases, the moving speed of the device is lQc
m/m1n). In other words, there is no need to cut with a laser with a high power exceeding 10KW,
If fusing is repeatedly performed with a low power laser of less than KW, the same result as cutting with a high power laser will be obtained. The figure shows a cutting depth of 85 mm when a laser with an output of 5 KW is used and cutting is performed twice at a cutting speed of 10 cm/min.The figure shows a cutting depth of 82 mm when cutting is performed once at a cutting speed of 5 cm/min It also shows that it is larger than

〔Effect of the invention〕

As explained above, according to the present invention, solid materials such as concrete materials can be easily cut by repeated fusing with a low-power laser, and results better than those obtained by cutting with a high-power laser can be obtained. Therefore, there is no need for large-scale devices (laser oscillators, power supplies, etc.) and incidental equipment for high output, which is extremely advantageous in terms of safety and cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the first embodiment according to the present invention, Fig. 2 is a schematic diagram of the second embodiment, Fig. 3 is a schematic diagram of the third embodiment, and Fig. 4 is a schematic diagram of the laser output. A diagram showing the relationship with cutting depth, FIG. 5 is a schematic diagram of a conventional example. 2... Laser irradiation device (processing head), 5.
... Laser beam, 6 ... Solid material (concrete material), 10 ... Molten slag, 12 ...
...Rotary cutter, 13...Cleaning device, 17...
... Plast nozzle, 18 ... Suction tube, 1
9... Supply pipe, 13.17, 18°19...
...shot blasting device. Patent applicant Taisei Corporation Agent Patent attorney Tetsuya Mori Attorney Yoshiaki Naito Attorney Patent attorney Tadashi Shimizu Figure 1←ε

Claims (2)

[Claims] (1) When cutting solid materials by laser irradiation, in order to repeatedly fuse the same cutting position, the focal position of the laser beam is moved in the direction of the welding depth depending on the welding depth each time, and the A method for cutting a solid material by laser irradiation, which comprises cutting while removing and cleaning slag produced by melting the solid material using a rotary cutter, shot blasting, or the like. (2) Equipped with a laser irradiation device configured to be able to move the focal position of the laser beam in the direction of the melting depth of the solid material, and a rotary cutter or shot blasting device for removing and cleaning slag from the melted solid material. A laser cutting device characterized by: